Construction started in 1450, under Pope Nicholas V, was funded by the Confraternity of Our Lady of Mercy.
During World War II, it was damaged by a bomb. The bomb was dropped by an Italian plane painted with German identification marks, as part of a scheme the fascists had cooked up. It was intended for San Pietro in Vaticano, but for some reason - either an error made by the bombardier or reluctance to bomb the world's greatest cathedral - it hit this church in the shadow of the basilica instead.
The church is served by German clergy.
The main point of interest here is the German cemetery. It was established so that Germans who died in Rome could rest among the martyrs. Dignitaries from other countries in northern Europe are also buried here.
In the Piazza dei Protomartiri Cristiani in front of the cemetery there is a bronze plaque marking the original site of the obelisk in Piazza San Pietro. Be careful if you look for it - there is quite a lot of traffic in and out of the Vatican at times.
The church is connected to the German college.
The interior of the church clearly shows its main purpose - to be used in funerals at the German cemetery. The recurring subject it death, with skeletons grinning from every corner.